Wireless devices, such as cellular telephones, have become widely used in daily life. As wireless devices are increasingly used for business, personal and emergency communication, it is becoming more and more important that wireless devices be made available for use by people who have physical or other limitations. In addition, the Federal Communications Commission (FCC) has mandated that cellular telephone service providers must begin providing cellular telephones that can be used by the hearing impaired.
A conventional, unmodified cellular telephone has shortcomings when used by a person wearing a hearing aid. The cellular signal that is generated by the telephone during a telephone call is received as input by the hearing aid, which then converts the signal into noise. The hearing aid user may detect this noise and, as a result, the signal quality of the call is degraded.
A conventional solution to this problem involves the uses of a Subscriber Identity Module (SIM) card that is configured to operate in place of a user's hearing aid. For example, a SIM card is configured with a user's hearing aid prescription so the user does not have to wear his or her hearing aid during a conversation, thereby eliminating any chance of hearing aid interference. A drawback of this conventional solution is that the SIM card is specifically tailored to the user's hearing aid prescription for a particular ear (i.e., the hearing aid in the left or right ear). If the user switches ears while using the cellular telephone, and has a different prescription for that ear, the SIM card may not be set properly. Thus, upon switching ears the user may notice that the volume level of the telephone is too low or too high. An additional drawback of this solution is that anyone other than the user for which the SIM is configured would likely encounter the same problem. To achieve normal volume levels on such a cellular telephone, a user would have to replace the SIM card with another SIM card that is not configured with the hearing aid prescription. This process is complicated and time-consuming for the average cellular telephone user. An additional drawback is the inconvenience and social awkwardness of requiring a user to remove his or her hearing aid prior to using the cellular telephone.
Another solution may involve reducing the power output of a wireless device to reduce the resulting interference with a hearing aid. However, simply manufacturing a wireless device, such as a telephone, having a permanently reduced power output can reduce the device's coverage area and signal quality because less power is available to transmit the user's signal. The issues of reduced coverage area and signal quality are particularly pronounced when the telephone is used for emergency purposes (e.g., to dial 911), where the greatest signal strength would typically be desired to ensure that the emergency call is successfully completed.
A solution may be to switch the wireless device into and out of the reduced power mode as needed. However, switching the device may not be a simple process for an average user, as several steps may need to be taken to effectuate the switch. A typical switching process may require a user to set the reduced power preference prior to making a call, or even more difficult, prior to answering an incoming call. A user may also have to program the device to enter a desired mode upon start up. If the device's start up mode is not the desired mode for a particular call, the user will have to switch modes again. The repetitive switching between modes can become tedious for the user. In addition, a user who is under the stress of an emergency situation may not be able to recall the proper method of switching power modes prior to placing an emergency call when full power may be desirable or alternatively, in such an emergency wherein reduced power is not a concern, but rather interference reduced operation is desirable.
An additional shortcoming is that the user may simply switch the device to the reduced power mode and leave it there unnecessarily, which may become a problem in the event that an emergency call needs to be made or should other users use the device. Furthermore, extended use in the reduced power mode may cause the user (or other users) to form an unfavorable opinion of the coverage area provided by a cellular service provider because of the gaps in coverage that may arise while the device is operating in the reduced power mode. In other words, the user may not realize that the gaps are due to the reduced power output of his or her device, rather than an actual coverage problem caused by the provider.
Accordingly, there is a need for a mechanism that enables simplified activation and deactivation of a reduced power mode in a wireless device that also minimizes unnecessary time spent in the reduced power mode. The present invention satisfies this need.